Enhancing OSPF to provide adaptive traffic distribution with networks for improved QoS performance

Tasir, ARM

Abstract

In recent years the growth in demand for multimedia applications delivered over a
network has been extensive illustrated by the phenomenal expansion of the World Wide
Web in today's Internet. Increasing amounts of electronic information are presented in
a multimedia format and delivered over networks, which generates increased traffic
demands. In short, future networks will not only comprise multiple, interconnected data
transport platforms but will also need to handle an increasing range of distributed
multimedia services, delivered to a diverse user community that is increasingly
becoming mobile.
However, this vision can only be realised if the underlying network infrastructure is
capable of providing the appropriate Quality of Service (QoS) guarantees. The only
limitation is that bandwidth will always remain a finite resource and whilst 'throwing
bandwidth' at the network may provide short-term relief, in the medium and long term,
users grow their demand to equal and finally surpass the capacity of the network.
As the network is a finite resource, effective usage is very important without
compromising the applications in the process. Thus, a substantial body of research is
being conducted into the development of QoS routing policies, which are able to direct
traffic over a connectionless, best effort delivery platform whilst trying to satisfy the
end-to-end application's QoS requirements.
In existing IP data networks, routing is concerned with connectivity and typically
supports only one type of datagram service called "Best Effort Routing". Routing
protocols such as OSPF in the main only use shortest-path algorithms and an arbitrary
single metric such as hop count, for optimal path computation. Therefore, routing
protocols need to have a more complex model to support QoS requirements. The basic
problem of QoS-based routing is then to find a path that satisfies multiple QoS
constraints and resource utilisation efficiency.
This thesis reports on research work that has investigated how OSPF can be enhanced to
provide an adaptive traffic routing algorithm that aims to assign, and dynamically reassign,
traffic flows to routes based on current utilisation. In this way overall traffic can
be more efficiently distributed across the network topology, thereby delaying the onset
of congestion and improving overall end-to-end delay times. A new traffic distribution
algorithm has been developed and integrated within OSPF. This, in turn, has been
simulated using the OPNET Modeler® simulator and proven to offer improved QoS
performance over standard OSPF. Studies have also been carried out to evaluate
behavioural characteristics of the new algorithm resulting from the dynamic reassignment
of traffic flows. Whilst the implementation has concentrated on OSPF, the
work has broader application to other routing protocols.
In conclusion, a new adaptive traffic distribution algorithm is proposed to enhance the
performance of OSPF and hence, contribute to the broader body of knowledge in field
of QoS based routing.

Citation

Tasir, A. Enhancing OSPF to provide adaptive traffic distribution with networks for improved QoS performance. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: Aug 19, 2021
• Award Date: Apr 1, 2007